This project involves the resynthesis of compounds not available on the open market or from the original supplier in amounts required by the Cancer Treatment Program. Compounds assigned for preparation are for completion of definitive testing or clinical or pre-clinical evaluations. Assignment of compound will originate with the Pharmaceutical Resources Branch, NCI, and involve a wide variety of chemical structures. Some of the effort will be devoted to the preparation of kilogram quantities of material requiring pilot plans facilities. Many preparations will involve multi-step sequences.